Endoscope system, control method, and recording medium

Abstract

Provided is an endoscope system, a control method, and a recording medium storing a control program, which enable display of a high-quality real-time image based on imaging with normal light while also enabling imaging with special light. An imaging element (23) images at a higher frame rate than the frame rate of display of an imaging image displayed by a display device (7). A light source device (5) repeatedly performs the following actions: after continuously irradiating illumination light during a first period spanning a plurality of consecutive frames of imaging by the imaging element (23), irradiating illumination light having a different spectrum from the illumination light irradiated during the first period during a second period spanning at least one frame of imaging by the imaging element (23).

Description

TECHNICAL FIELD

[0001] The present application relates to an endoscope system, a control method, and a recording medium storing a control program. BACKGROUND

[0002] Conventionally, an endoscope system is known which performs continuous imaging while irradiating normal light such as white light to an object, and displays a real-time image. An endoscope system is known which performs continuous imaging while irradiating special light such as narrow-band light to an object, and performs analysis such as IEE (Image-Enhanced Endoscopy).

[0003] Further, an endoscope system is known which is capable of switching normal light and special light as illumination light at the time of imaging. For example, in Patent Document 1, an endoscope system is described which has a special observation mode in which normal light and special light are alternately irradiated via an extinguishing period, and signal reading from an imaging element is performed during each extinguishing period. In Patent Document 2, an endoscope system is described which acquires a special light image generated by imaging during irradiation of special light to an object, and a normal light image generated by imaging during irradiation of normal light to the object.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT DOCUMENTS

[0006] Patent Document 1: WO2015 / 136963

[0007] Patent Document 2: Japanese Patent Application Publication No. 2016-19569 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] However, in the above-described conventional technology, it is not possible to perform display of a high-quality real-time image based on imaging with normal light, while also performing imaging based on special light. For example, if imaging is performed while switching normal light and special light, the frame rate of the imaging image information used in the real-time image at the time of normal light decreases, and thus the frame rate of the display of the real-time image decreases, and thus it is not possible to perform display of a high-quality real-time image.

[0010] Further, in the structure of Patent Document 1, since normal light and special light are alternately irradiated, the exposure time of the normal light becomes short, and thus it is not possible to perform display of a high-quality real-time image. Further, in Patent Document 2, there is no disclosure of a means to solve the above-described problem.

[0011] The present application has been achieved in view of the above-described circumstances, and aims to provide an endoscope system, a control method, and a recording medium storing a control program, which enable display of a high-quality real-time image based on imaging with normal light while also performing imaging based on special light.

[0012] Means for solving technical problems

[0013] The endoscope system of the present application includes an endoscope including an imaging unit, a light source unit that irradiates illumination light to an imaging target imaged by the imaging unit, an imaging control unit that generates imaging image information from an imaging signal obtained from the imaging unit, and a display unit that displays an imaging image based on the imaging image information, the imaging unit performs imaging of the imaging target at a higher frame rate than the display of the imaging image displayed by the display unit, and the light source unit repeatedly performs the following actions: after continuously irradiating illumination light for a first period spanning a plurality of frames continuously imaged based on the imaging unit, irradiating illumination light having a different spectrum from the illumination light irradiated during the first period for a second period spanning at least one frame based on the imaging by the imaging unit.

[0014] In the control method of the endoscope system of the present application, the endoscope system includes an endoscope including an imaging unit, a light source unit that irradiates illumination light to an imaging target imaged by the imaging unit, an imaging control unit that generates imaging image information from an imaging signal obtained from the imaging unit, and a display unit that displays an imaging image based on the imaging image information, the imaging unit performs imaging of the imaging target at a higher frame rate than the display of the imaging image displayed by the display unit, and the light source unit repeatedly performs the following actions: after continuously irradiating illumination light for a first period spanning a plurality of frames continuously imaged based on the imaging unit, irradiating illumination light having a different spectrum from the illumination light irradiated during the first period for a second period spanning at least one frame based on the imaging by the imaging unit.

[0015] Also, a control program for the present application stored in a recording medium controls an endoscope system having: an endoscope having an imaging section; a light source section that irradiates an imaging object imaged by the imaging section with illumination light; an imaging control section that generates imaging image information from an imaging signal obtained from the imaging section; and a display section that displays an imaging image based on the imaging image information, the control program for causing a computer to execute processing of causing the imaging section to image the imaging object at a higher frame rate than a display frame rate of the imaging image displayed by the display section, and causing the light source section to repeatedly perform the following actions: continuously irradiating the imaging object with illumination light across a first period of a plurality of frames based on imaging by the imaging section, and irradiating the imaging object with illumination light having a different spectrum from the illumination light irradiated in the first period across a second period of at least one frame based on imaging by the imaging section.

[0016] Effects of Invention

[0017] According to the present application, an endoscope system, a control method, and a recording medium storing a control program that enables display of a high-quality real-time image based on imaging using normal light while also enabling imaging based on special light can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a diagram showing an example of an endoscope apparatus 100 according to an embodiment of the present application.

[0019] Figure 2 is a diagram showing an example of the internal structure of the endoscope apparatus 100 shown in Figure 1

[0020] Figure 3 is a diagram showing an example of the spectrum of light generated by the light source apparatus 5 shown in Figure 2

[0021] Figure 4 is a diagram showing an example of the outline structure of the imaging element 23 shown in Figure 2

[0022] Figure 5 is a diagram showing an example of a functional block diagram of the system control section 44 of the signal processing section 42 shown in Figure 2

[0023] Figure 6 is a diagram showing an example of a screen displayed on the display apparatus 7.

[0024] Figure 7 is a diagram showing an example of a timing chart of the respective actions in the endoscope apparatus 100.

[0025] Figure 8 ​​​​is a drawing showing an example of a timing chart of each action in the modified example 1 of the endoscope apparatus 100.

[0026] Figure 9 is a drawing showing an example of a timing chart of each action in the modified example 2 of the endoscope apparatus 100. DETAILED DESCRIPTION

[0027] Hereinafter, an embodiment of the present application will be described with reference to the drawings.

[0028] Figure 1 is a drawing showing an example of the endoscope apparatus 100 of an embodiment of the present application.

[0029] The endoscope apparatus 100 is an example of an endoscope system of the present application. As shown in Figure 1 , the endoscope apparatus 100 is provided with an endoscope 1, and a control apparatus 4 and a light source apparatus 5 connected to the endoscope 1. The control apparatus 4 constitutes an imaging control section of the present application. The light source apparatus 5 constitutes a light source section of the present application.

[0030] The control apparatus 4 is connected to a display apparatus 7 and an input section 6, the display apparatus 7 displays an imaging image and the like obtained by imaging an inside of a subject with the endoscope 1, and the input section 6 is an interface for inputting various information to the control apparatus 4. The control apparatus 4 controls the endoscope 1, the light source apparatus 5, and the display apparatus 7.

[0031] The display apparatus 7 has a display surface in which display pixels are arranged in two dimensions, and performs display of an image based on image data by drawing pixel data constituting the image data on each display pixel of the display surface. The display apparatus 7 constitutes a display section that switches a display image in accordance with an instruction from the control apparatus 4.

[0032] The endoscope 1 includes an insertion section 10 that is a tubular member extending in one direction and is inserted into an inside of a subject, an operation section 11 that is provided at a proximal end section of the insertion section 10 and is provided with operation members for performing an observation mode switching operation, an imaging recording operation, a forceps operation, a gas / water feeding operation, a suction operation, and the like, a bend angle knob 12 that is provided adjacent to the operation section 11, and a universal cord 13 that includes connector sections 13A, 13B for detachably connecting the endoscope 1 to the control apparatus 4 and the light source apparatus 5.

[0033] In addition, although omitted in Figure 1 , various channels such as a forceps hole into which a forceps for collecting biological tissues such as cells or polyps is inserted, a gas / water feeding channel, a suction channel, and the like are provided in the operation section 11 and the inside of the insertion section 10.

[0034] The insertion section 10 is composed of a flexible section 10A having flexibility, a bent section 10B provided at the front end of the flexible section 10A, and a front end section 10C provided at the front end of the bent section 10B and having rigidity.

[0035] The bent section 10B is configured to be bent freely by a turning operation of the bend knob 12. The bent section 10B can be bent in any direction and at any angle according to the site of the subject using the endoscope 1, and thus the front end section 10C can be directed toward a desired direction.

[0036] Figure 2 is a schematic view showing the internal structure of the endoscope device 100. Figure 1 is a schematic view showing the internal structure of the endoscope device 100. Figure 3 is a schematic view showing the internal structure of the endoscope device 100. Figure 2 is a view showing an example of a spectrum of light generated by the light source device 5.

[0037] The light source device 5 can switch and irradiate normal light and special light as illumination light. The normal light is light having a light emission spectrum suitable for recognition by a human such as a doctor, and the like, such as white light. The special light is light having a light emission spectrum different from that of the normal light, and suitable for analysis by a computer such as an IEE, and the like.

[0038] Specifically, the light source device 5 includes a light source processor 51, a light source section 52, and a light path coupling section 54. The light source processor 51 is connected to the system control section 44 of the control device 4, and controls the light source section 52 according to an instruction from the system control section 44.

[0039] The light source section 52 has, for example, a plurality of semiconductor light sources, and turns them on or off, respectively, and in the case of turning on, emits illumination light for illuminating an observation object by controlling the light emission amount of each semiconductor light source. In the present embodiment, the light source section 52 has LEDs of four colors, V-LED (Violet Light Emitting Diode), B-LED (Blue Light Emitting Diode), G-LED (Green Light Emitting Diode), and R-LED (Red Light Emitting Diode).

[0040] The light source processor 51 can emit light by independently controlling the V-LED 52a, the B-LED 52b, the G-LED 52c, and the R-LED 52d, respectively, so as to independently change the light amount of the violet light V, the blue light B, the green light G, or the red light R, respectively. As shown in Figure 3As shown, the V-LED 52a generates purple light V having a center wavelength of 405 ± 10 nm and a wavelength range of 380 to 420 nm. The B-LED 52b generates blue light B having a center wavelength of 450 ± 10 nm and a wavelength range of 420 to 500 nm. The G-LED 52c generates green light G having a wavelength range of 480 to 600 nm. The R-LED 52d generates red light R having a center wavelength of 620 to 630 nm and a wavelength range of 600 to 650 nm.

[0041] Also, when the normal light is irradiated, the light source processor 51 controls the respective LEDs 52a to 52d so that the light amount ratio among the purple light V, the blue light B, the green light G, and the red light R becomes Vc : Bc : Gc : Rc of white light emission. In addition, Vc, Bc, Gc, Rc > 0.

[0042] Also, when the special light is irradiated, the light source processor 51 controls the respective LEDs 52a to 52d so that the light amount ratio among the purple light V, the blue light B, the green light G, and the red light R, which are narrow-band lights of short wavelengths, becomes Vs : Bs : Gs : Rs of special light emission.

[0043] The light amount ratio Vs : Bs : Gs : Rs is different from the light amount ratio Vc : Bc : Gc : Rc used when the normal light is irradiated, and is appropriately determined according to the observation purpose. For example, in a case where the superficial blood vessels are emphasized, it is preferable to make Vs larger than the other Bs, Gs, and Rs, and in a case where the deep blood vessels are emphasized, it is preferable to make Gs larger than the other Vs, Bs, and Rs.

[0044] The light path coupling section 54 couples the respective lights emitted from the V-LED 52a, the B-LED 52b, the G-LED 52c, and the R-LED 52d, and emits the coupled light as illumination light. The illumination light emitted from the light path coupling section 54 of the light source section 52 is incident on the light guide 53 described later, which is built in the general plug cord 13, and is irradiated onto the subject through the illumination lens 50 provided at the front end portion 10C of the insertion portion 10.

[0045] The front end portion 10C of the endoscope 1 is provided with an imaging optical system including the objective lens 21 and the lens group 22, an imaging element 23 that photographs a subject by passing through the imaging optical system, a memory 25 such as a RAM (Random Access Memory), a communication I / F (Interface) 26, an imaging drive section 27, and a light guide 53 for guiding the illumination light emitted from the light source section 52 to the illumination lens 50. The imaging element 23 constitutes an imaging section of the present application.

[0046] The light guide 53 extends from the front end portion 10C to the connector portion 13A of the general-purpose plug cord 13. In a state where the connector portion 13A of the general-purpose plug cord 13 is connected to the light source device 5, the illumination light emitted from the light source portion 52 of the light source device 5 becomes a state where it can be incident on the light guide 53.

[0047] The imaging element 23 can use a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like. In the present embodiment, the imaging element 23 is a CMOS using a rolling shutter.

[0048] The imaging element 23 has a light-receiving surface on which a plurality of pixels are arranged in a two-dimensional manner, and converts an optical image formed on the light-receiving surface by the above-described imaging optical system into an electric signal (imaging signal) in each pixel. Then, the imaging element 23 converts the converted imaging signal from an analog signal into a digital signal of a prescribed number of bits, and outputs the imaging signal converted into the digital signal to the memory 25. The imaging element 23 can use, for example, an imaging element on which a color filter of a primary color or a complementary color, or the like is mounted. A set of the imaging signals output from each pixel of the light-receiving surface of the imaging element 23 is referred to as an imaging image signal.

[0049] The imaging element 23 can be arranged at the front end portion 10C in a state where the light-receiving surface is perpendicular to the optical axis Ax of the objective lens 21, or can be arranged at the front end portion 10C in a state where the light-receiving surface is parallel to the optical axis Ax of the objective lens 21.

[0050] The imaging optical system provided on the endoscope 1 is constituted by the objective lens 21 and optical members (including the above-described lens group 22) such as lenses, prisms, and the like that are located on an optical path of light from an object of photographing between the imaging element 23 and the objective lens 21. The imaging optical system is sometimes constituted only by the objective lens 21.

[0051] The memory 25 temporarily records the digital imaging signal output from the imaging element 23.

[0052] The communication I / F 26 is connected to the communication interface (I / F) 41 of the control device 4. The communication I / F 26 transmits the imaging signal recorded in the memory 25 to the control device 4 through a signal line inside the general-purpose plug cord 13.

[0053] The imaging drive section 27 is connected to the system control section 44 of the control device 4 via the communication I / F 26. The imaging drive section 27 drives the imaging element 23 and the memory 25 in accordance with an instruction from the system control section 44 received by the communication I / F 26.

[0054] The control device 4 includes a communication I / F 41 connected to the communication I / F 26 of the endoscope 1 via a general-purpose plug cord 13, a signal processing section 42, a display controller 43, a system control section 44, and a recording medium 45.

[0055] The communication I / F 41 receives an imaging signal transmitted from the communication I / F 26 of the endoscope 1 and passes it to the signal processing section 42.

[0056] The signal processing section 42 includes a memory that temporarily records the imaging signal received from the communication I / F 41, and processes (image processing such as demosaicing processing or gamma correction processing) an imaging image signal that is a set of the imaging signal recorded in the memory to generate imaging image information in a form in which recognition processing or the like can be performed. The imaging image information generated by the signal processing section 42 is recorded in the recording medium 45 such as a hard disk or a flash memory.

[0057] The display controller 43 displays an imaging image based on the imaging image information generated by the signal processing section 42 on the display device 7. The coordinates of each pixel data that constitutes the imaging image information generated by the signal processing section 42 are managed in association with the coordinates of any one display pixel that constitutes the display surface of the display device 7.

[0058] The system control section 44 controls each section of the control device 4 and transmits an instruction to the imaging drive section 27 of the endoscope 1 and the light source processor 51 of the light source device 5, thereby collectively controlling the entire endoscope device 100. For example, the system control section 44 performs control of the imaging element 23 via the imaging drive section 27. Also, the system control section 44 performs control of the light source section 52 via the light source processor 51.

[0059] The system control section 44 or the signal processing section 42 includes various processors that perform processing by executing programs, a RAM, and a ROM.

[0060] As the various processors, there are a general-purpose processor, that is, a CPU (Central Processing Unit) that performs various processing by executing programs, a FPGA (Field Programmable Gate Array), and the like, a programmable logic device (PLD) or an ASIC (Application Specific Integrated Circuit) having a circuit structure specially designed for performing a specific processing, and the like, and a dedicated circuit having a circuit structure specially designed for performing a specific processing.

[0061] More specifically, the structures of these various processors are circuits in which circuit elements such as semiconductor elements are combined.

[0062] The system control section 44 or the signal processing section 42 can be constituted by one of various processors, or can be constituted by a combination of two or more processors of the same kind or different kinds (for example, a combination of a plurality of FPGAs or a combination of a CPU and an FPGA).

[0063] Figure 4 is a plan view schematically showing the structure of the imaging element 23. Figure 2

[0064] The imaging element 23 includes an imaging surface 60 in which a plurality of pixel rows 62 formed of a plurality of pixels 61 arranged in a row direction X are arranged in a column direction Y orthogonal to the row direction X, a drive circuit 63 that drives the pixels 61 arranged on the imaging surface 60, and a signal processing circuit 64 that processes pixel signals read out to signal lines from the respective pixels 61 of the pixel rows 62 arranged on the imaging surface 60. The imaging surface 60 constitutes a light-receiving surface.

[0065] Hereinafter, in Figure 4 the column direction Y of the imaging surface 60 is referred to as an upper end, and an end portion on the other end side (lower side in the drawing) of the column direction Y of the imaging surface 60 is referred to as a lower end.

[0066] Figure 4 The drive circuit 63 shown in Fig. 6 drives each of the pixel rows 62 independently in accordance with a signal from the imaging drive section 27, and performs reset (discharge of electric charges accumulated in photoelectric conversion elements) of each of the pixels 61 included in the pixel row 62, readout of a pixel signal corresponding to electric charges accumulated in the photoelectric conversion element of the each of the pixels 61 to a signal line, and the like.

[0067] Figure 4 The signal processing circuit 64 shown in Fig. 6 performs correlated double sampling processing on the pixel signals read out to the signal lines from the respective pixels 61 of the pixel rows 62, and outputs the pixel signals after the correlated double sampling processing as digital signals. The signal processing circuit 64 is controlled by the imaging drive section 27.

[0068] The signal processing section 42 performs signal processing such as demosaicing processing and gamma correction processing on the pixel signals output from the imaging element 23, and generates imaging image information.

[0069] The endoscope device 100 is equipped with a continuous shooting mode that continuously generates a plurality of imaging image information in accordance with one imaging instruction. In the continuous shooting mode, the system control section 44 causes the imaging element 23 to be driven in a rolling shutter manner by the imaging drive section 27, and the subject is imaged.

[0070] ​The drive of the rolling shutter method includes a rolling reset drive and a rolling readout drive. The rolling reset drive is a drive in which the process of resetting each pixel 61 of the pixel row 62 and starting exposure of the pixel 61 is sequentially performed while the pixel row 62 is changed. The rolling readout drive is a drive in which the process of reading out a signal from each pixel 61 of the pixel row 62 that has been exposed and ending exposure of the pixel row 62 is sequentially performed while the pixel row 62 is changed.

[0071] Figure 5 is a functional block diagram of the system control section 44 of the signal processing section 42. Figure 2 is an example of a functional block diagram of the system control section 44 of the signal processing section 42.

[0072] The processor of the signal processing section 42 functions as a control device having a captured image information generation section 42a, a real-time image generation section 42b, an analysis section 42c, and an analysis image generation section 42d by executing a control program stored in a ROM built in the signal processing section 42.

[0073] The captured image information generation section 42a generates captured image information by performing image processing such as demosaicing processing or gamma correction processing on a captured signal obtained by imaging by the imaging element 23. The captured image information generation section 42a outputs, as captured frames, captured image information based on a captured signal obtained by imaging when the normal light is irradiated to the real-time image generation section 42b and captured image information based on a captured signal obtained by imaging when the special light is irradiated to the analysis section 42c. The captured frame is a captured signal obtained by one-time imaging.

[0074] The real-time image generation section 42b generates real-time image information for displaying a real-time image from the captured frames output from the captured image information generation section 42a, and outputs the generated real-time image information as captured image information to the display controller 43 (see Fig. 1). The real-time image is an image (animation) that displays the result of continuous imaging by the imaging element 23 in real time, and constitutes the captured image of the present application. Figure 2 ). The real-time image is an image (animation) that displays the result of continuous imaging by the imaging element 23 in real time, and constitutes the captured image of the present application.

[0075] The analysis section 42c performs analysis based on the captured frames output from the captured image information generation section 42a, and outputs the analysis result to the analysis image generation section 42d. Among them, the analysis image generation section 42d is configured to perform processing of extracting the outline of the captured image as analysis.

[0076] For example, the analysis section 42c determines the outline of a biological structure reflected in the image represented by the imaging image information obtained by imaging while the special light is being irradiated. The biological structure of the specific object is, for example, a superficial vascular structure, an intermediate vascular structure, or a deep vascular structure, or the like. The analysis image generation section 42d generates image information of an outline emphasized image that emphasizes the outline determined by the analysis section 42c in the image represented by the imaging image information obtained by imaging while the special light is being irradiated. Thereby, the outline emphasized image is displayed on the sub screen 72, and the operator of the endoscope 1 can easily recognize the structure in the subject.

[0077] The analysis image generation section 42d generates IEE image information for displaying an IEE image representing the analysis result output from the analysis section 42c, and outputs the generated IEE image information to the display controller 43 as the imaging image information (refer to Figure 2 ). The IEE image is an image that emphasizes the outline of the structure of the subject based on the imaging signal obtained by imaging while the special light such as blue laser light is being irradiated. At this time, the special light such as blue laser light constitutes the light for image enhanced observation. For example, the IEE image is an image that emphasizes a superficial vascular structure, an image that emphasizes an intermediate vascular structure, an image that emphasizes a deep vascular structure, or the like.

[0078] In addition, the image generated by the analysis image generation section 42d is not limited to the imaging image or the image obtained by processing the imaging image, and can be an image representing a numerical value (quantity, accuracy, or the like) or a character (tumor category), or the like based on the analysis performed by the analysis section 42c.

[0079] As explained in Figure 5 , the endoscope device 100 is provided with the analysis section 42c that performs analysis based on the imaging image information obtained by imaging during the second period when the special light is being irradiated. On the other hand, the endoscope device 100 displays a real-time image based on the imaging image information obtained by imaging during the first period when the normal light is being irradiated. Thereby, it is possible to perform analysis based on the special light while displaying the real-time image based on the normal light.

[0080] Figure 6 is a drawing representing an example of a screen displayed on the display device 7.

[0081] The display controller 43 displays, for example, the screen 70 shown in Figure 6 on the display device 7 based on the imaging image information output from the signal processing section 42. The screen 70 includes a main screen 71 and a sub screen 72.

[0082] A real-time image based on real-time image information output from the real-time image generation section 42b of the signal processing section 42 is displayed on the main screen 71. An IEE image based on IEE image information output from the analysis image generation section 42d of the signal processing section 42 is displayed on the sub screen 72.

[0083] As explained in Figure 6 , the endoscope device 100 displays the screen 70 containing a real-time image based on image information obtained by imaging during the first period in which normal light is irradiated and an analysis result based on image information obtained by imaging during the second period in which special light is irradiated.

[0084] Figure 7 is a drawing showing an example of a timing chart of each action in the endoscope device 100.

[0085] The illumination light timing 81 is a timing at which the light source device 5 irradiates illumination light according to an instruction from the control device 4. The WLI in the illumination light timing 81 is a timing at which the light source device 5 irradiates normal light such as white light as illumination light. The IEE1 in the illumination light timing 81 is a timing at which the light source device 5 irradiates first special light such as narrow-band light as illumination light. The IEE2 in the illumination light timing 81 is a timing at which the light source device 5 irradiates second special light different from the first special light as illumination light.

[0086] As shown in the illumination light timing 81, the light source device 5 repeatedly performs a predetermined irradiation action with a period T. The irradiation action is an action of irradiating normal light and then irradiating special light (first special light or second special light). In the example shown in Figure 7 , the light source device 5 alternately switches the special light to be irradiated to the first special light and the second special light every period T. However, the light source device 5 can irradiate only the first special light every period T.

[0087] The imaging timing 82 is a timing at which the imaging element 23 performs imaging (exposure) according to an instruction from the control device 4. The vertical direction in the imaging timing 82 indicates the position of the column direction Y of the pixel row 62 (see Figure 4 ). As described above, the imaging element 23 in the present embodiment performs imaging in the rolling shutter method, and thus the imaging timing 82 is staggered every pixel row 62. In the example shown in Figure 7 , the imaging element 23 performs imaging at a frame rate of 90 fps (frames per second).

[0088] As shown in the illumination light timing 81 and the imaging timing 82, the light source device 5 continuously irradiates normal light during the first period that spans a plurality of frames in succession based on imaging by the imaging element 23. Also, the light source device 5 continuously irradiates special light during the second period that spans at least one frame based on imaging by the imaging element 23. In the example shown in Figure 7In the illustrated example, the 2nd period spans a plurality of frames that are continuous based on imaging by the imaging element 23.

[0089] The main screen display timing 83 is a timing at which the display device 7 displays (draws) the main screen 71 according to an instruction from the control device 4. In the illustrated example, the main screen 71 is displayed by the display device 7 at a frame rate that is lower than 60 fps, that is, a frame rate based on imaging by the imaging element 23. The sub screen display timing 84 is a timing at which the display device 7 displays (draws) the sub screen 72 according to an instruction from the control device 4. Figure 7

[0090] As indicated by the illumination light timing 81, the imaging timing 82, and the main screen display timing 83, the display device 7 displays the main screen 71 based on an imaging signal obtained by imaging at the time of illumination by the normal light in each of the imaging indicated by the imaging timing 82. For example, the display device 7 performs main screen display 83a based on an imaging signal obtained by the imaging 82a.

[0091] Also, as indicated by the illumination light timing 81, the imaging timing 82, and the sub screen display timing 84, the display device 7 displays the sub screen 72 based on an imaging signal obtained by imaging at the time of illumination by the special light in each of the imaging indicated by the imaging timing 82. For example, the display device 7 performs sub screen display 84b (display of the analysis result of IEE1) based on an imaging signal obtained by the imaging 82b at the time of the first illumination by the special light (IEE1). Also, the display device 7 performs sub screen display 84c (display of the analysis result of IEE2) based on an imaging signal obtained by the imaging 82c at the time of the second illumination by the special light (IEE2).

[0092] Also, the control device 4 performs blank reading of an imaging signal obtained by imaging at the timing at which the illumination light illuminated by the light source device 5 is switched from the normal light to the special light in each of the imaging indicated by the imaging timing 82. The blank reading of the imaging signal means that an image based on the imaging signal is not displayed by the display device 7, for example, discarding of the imaging signal. For example, the control device 4 performs reading out of a pixel signal corresponding to the electric charge accumulated in the photoelectric conversion element to a signal line, and at the same time as discharging the electric charge accumulated in the photoelectric conversion element in the same manner as the above-described reset, discards the read out signal. Note that the discarding of the read out signal can be performed in the endoscope 1 or in the control device 4.

[0093] For example, the control device 4 discards the imaging signal obtained by the imaging 82d. Thereby, even if the global reset is not performed at the timing at which the illumination light illuminated by the light source device 5 is switched from the normal light to the special light, it is possible to suppress the influence of the switching of the illumination light on the above-described analysis or the display of the main screen 71.

[0094] ​For example, if the imaging signal obtained by imaging including the timing at which the illumination light is switched from the normal light to the special light is used in the above analysis, the above analysis cannot be properly performed due to the switching of the illumination light, and the content of the analysis result image displayed on the sub screen 72 becomes inaccurate. Also, if the imaging signal obtained by imaging including the timing at which the illumination light is switched from the normal light to the special light is used on the main screen 71, the color of the real-time image displayed on the main screen 71 temporarily changes due to the switching of the illumination light. By performing the above blank reading, the influence on the display of these main screen 71 or sub screen 72 can be suppressed.

[0095] Although not illustrated, the control device 4 can further perform blank reading of the imaging signal obtained by imaging including the timing at which the illumination light irradiated by the light source device 5 is switched from the special light to the normal light in the imaging at each timing indicated by the imaging timing 82. For example, the control device 4 can discard the imaging signal obtained by the imaging 82e. Thereby, even if the global reset is not performed at the timing at which the illumination light irradiated by the light source device 5 is switched from the special light to the normal light, the influence on the above analysis or the display of the main screen 71 due to the switching of the illumination light can be suppressed.

[0096] As explained in Figure 7 , the imaging element 23 can suppress the reduction in the frame rate of the display of the real-time image caused by the switching of the normal light and the special light by imaging at a higher frame rate than the frame rate displayed by the display device 7, and thereby can perform high-quality display of the real-time image.

[0097] Also, since the first period in which the light source device 5 continuously irradiates the normal light is longer than the second period in which the light source device 5 continuously irradiates the special light, for example, compared to a structure in which the normal light and the special light are alternately switched per frame in the imaging based on the imaging element 23, the exposure time when the normal light is irradiated can be extended, and thereby high-quality display of the real-time image can be performed.

[0098] Also, by performing the above blank reading at the timing at which the illumination light irradiated by the light source device 5 is switched, regarding the imaging signal after the second period in which the light source device 5 continuously irradiates the special light has just started, the imaging signal of at least the imaging signal based on the amount of 1 frame of the imaging element 23 can be acquired as the imaging signal displayed as the sub screen 72 of the display device 7. Thereby, even if the global reset is not performed at the timing at which the illumination light irradiated by the light source device 5 is switched, the influence on the analysis result due to the switching of the illumination light can be suppressed.

[0099] Since the global reset is not required to be performed, even in a structure in which the rolling shutter method of imaging is performed, a global reset circuit does not need to be provided on the imaging element 23, and the circuit scale can be suppressed.

[0100] Thus, in the endoscope device 100, the imaging element 23 images at a higher frame rate than the frame rate of display of the imaging image displayed by the display device 7. Then, the light source device 5 repeatedly performs the following actions: after continuously irradiating the illumination light across the first period based on the imaging of the imaging element 23 for a plurality of frames in succession, irradiating the illumination light having a different spectrum from the illumination light irradiated in the first period for a period, i.e., the second period, based on the imaging of the imaging element 23 for at least one frame. Thereby, without a switching operation of the illumination light based on the user, it is possible to perform the display of the high-quality real-time image based on the imaging based on the normal light while also performing the imaging based on the special light.

[0101] Figure 8 is a drawing representing an example of a timing chart of each action in the modified example 1 of the endoscope device 100.

[0102] The structure in which the global reset is not performed in the imaging element 23 by performing the blank reading has been described, but the structure in which the global reset is performed can also be provided. In the structure in which the global reset is performed, the global reset is performed in the imaging element 23 at the timing at which the illumination light irradiated by the light source device 5 is switched from the normal light to the special light. Figure 8 In the imaging timing 82, the black rectangle represents the timing at which the global reset of the imaging element 23 is performed.

[0103] In the example illustrated in Figure 8 , the imaging element 23 performs the global reset at the timing at which the illumination light irradiated by the light source device 5 is switched from the normal light to the special light instead of the above-described blank reading. For example, the imaging element 23 performs the global reset 91 at the timing between the imaging 82a and the imaging 82b. Thereby, even if the above-described blank reading is not performed at the timing at which the illumination light irradiated by the light source device 5 is switched from the normal light to the special light, it is possible to suppress the influence of the switching of the illumination light on the above-described analysis or the display of the main screen 71.

[0104] Although not illustrated, the control device 4 can further cause the imaging element 23 to perform the global reset at the timing at which the illumination light irradiated by the light source device 5 is switched from the special light to the normal light. For example, the control device 4 can perform the global reset instead of the imaging 82e. Thereby, even if the blank reading is not performed at the timing at which the illumination light irradiated by the light source device 5 is switched from the special light to the normal light, it is possible to suppress the influence of the switching of the illumination light on the above-described analysis or the display of the main screen 71.

[0105] As illustrated in Figure 8 , the global reset of the imaging element 23 is performed after the first period in which the normal light is irradiated, and the imaging image information after the global reset is acquired as the imaging image information of the second period in which the special light is irradiated. Thereby, it is possible to suppress the influence of the switching of the illumination light on the analysis result.

[0106] Figure 9 is a drawing representing an example of a timing chart of each action in the modified example 2 of the endoscope device 100.

[0107] In the above description, the imaging element 23 performs imaging using a rolling shutter method. However, the imaging element 23 may also perform imaging using a global shutter method. Figure 9 The imaging time 82 represents the imaging (exposure) time when the imaging element 23 performs imaging in a global shutter manner. Figure 9 As shown in the imaging time 82 , in the global shutter method, the imaging time is the same in each pixel row 62 .

[0108] At this time, if Figure 9 As shown, the light source device 5 switches the illumination light during the global shutter method of imaging. Thus, even if the global reset or the above-mentioned blank reading is not performed, the influence of the switching of the illumination light on the above-mentioned analysis or the display of the main screen 71 can be suppressed. Figure 9 As shown, the imaging element 23 can perform imaging operation using a global shutter method.

[0109] (Other examples of analysis)

[0110] While the analysis performed by the analyzing unit 42 c (signal processing unit 42 ) based on captured image information obtained by imaging under special light irradiation has been described as extracting the contour of the captured image, the analysis performed by the analyzing unit 42 c is not limited thereto.

[0111] For example, the analysis unit 42c can analyze the insertion shape of the endoscope 1 as the above-mentioned analysis. Specifically, the analysis of the insertion shape of the endoscope 1 is to determine the insertion shape of the insertion portion 10 of the endoscope 1 inserted into the subject. For example, the analysis unit 42c determines the insertion shape of the endoscope 1 based on changes in camera image information obtained by imaging when irradiating special light. The analysis image generation unit 42d generates image information for displaying an image representing the insertion shape of the endoscope 1 determined by the analysis unit 42c. As a result, the image representing the insertion shape of the endoscope 1 is displayed on the sub-screen 72, and the operator of the endoscope 1 can easily insert the insertion portion 10 of the endoscope 1 into the subject.

[0112] Alternatively, the analysis section 42c can perform detection of a region of interest in the subject into which the endoscope 1 is inserted as the above analysis. For example, the analysis section 42c detects a region of interest in the subject from an image represented by the captured image information obtained by the capturing at the time of irradiation with the special light. The region of interest is a region in the observation of the subject in which attention is recommended, such as a region in which a lesion is likely to be present, and the like. The analysis image generation section 42d generates image information of a region of interest emphasis image in which the region of interest detected by the analysis section 42c is emphasized in the image represented by the captured image information obtained by the capturing at the time of irradiation with the special light. Thereby, the region of interest emphasis image is displayed on the sub screen 72, and the operator of the endoscope 1 can easily recognize the region of interest in the subject. Alternatively, the analysis image generation section 42d can also generate image information of a color difference expansion image in which a color difference between an abnormal portion (a lesion portion, or the like) serving as the region of interest and a normal portion is expanded, which is displayed in the image represented by the captured image information obtained by the capturing at the time of irradiation with the special light. Thereby, the color difference expansion image is displayed on the sub screen 72, and the operator of the endoscope 1 can easily distinguish the abnormal portion and the normal portion in the subject.

[0113] Alternatively, the analysis section 42c can perform selection of a similar case image as the above analysis. For example, the analysis section 42c selects a case image similar to the captured image information obtained by the capturing at the time of irradiation with the special light by searching a database accessible by the endoscope device 100. The analysis image generation section 42d generates image information of an image representing a result of the selection by the analysis section 42c. The result of the selection by the analysis section 42c can be the case image selected by the analysis section 42c itself, or information such as a diagnosis result related to the case image, which is associated with the case image selected by the analysis section 42c in the above database. Thereby, the result of the selection of the similar case image is displayed on the sub screen 72, and the operator of the endoscope 1 can easily perform a comparison between the state in the subject in the observation and a similar case.

[0114] Alternatively, the analysis section 42c can perform discrimination of a tumor and a non-tumor as the above analysis. For example, the analysis section 42c discriminates whether a biological region reflected in the image represented by the captured image information obtained by the capturing at the time of irradiation with the special light is a tumor. The analysis image generation section 42d generates image information of an image representing a result of the discrimination by the analysis section 42c. The result of the discrimination by the analysis section 42c can be information representing whether a biological region reflected in an image most recently captured is a tumor, or information representing the number of biological regions discriminated as tumors after the start of the current examination, or the like. Thereby, the result of the discrimination of the tumor and the non-tumor is displayed on the sub screen 72, and the observation by the operator of the endoscope 1 or the operation of the endoscope 1 can be assisted.

[0115] Alternatively, the analysis section 42c can perform determination of the state of the organ as the above analysis. For example, the analysis section 42c determines the state of the organ reflected in the image represented by the captured image information obtained by the imaging at the time of irradiation with the special light. The state of the organ is, for example, the oxygen saturation of each region, the thickness, density, pattern, uniformity of the blood vessel structure, or the surface structure of the large intestine (for example, pit-like structure), the surface structure of the duodenum (for example, villus structure), and the like. The analysis image generation section 42d generates image information for displaying an image representing the result determined by the analysis section 42c. For example, the analysis image generation section 42d generates an oxygen saturation image that images the oxygen saturation of each determined region. Thereby, the determination result of the state of the organ is displayed on the sub screen 72, and observation by the operator of the endoscope 1 or operation of the endoscope 1 can be assisted.

[0116] Alternatively, the analysis section 42c can perform generation of the incision intended line as the above analysis. For example, the analysis section 42c determines an incision intended line (boundary line) in a biological region reflected in the image represented by the captured image information obtained by the imaging at the time of irradiation with the special light, which should be incised in order to remove a tumor or the like. The analysis image generation section 42d generates image information for displaying an image in which the incision intended line determined by the analysis section 42c is added to the image represented by the captured image information obtained by the imaging at the time of irradiation with the special light. Thereby, the image to which the incision intended line is added is displayed on the sub screen 72, and the operator of the endoscope 1 can easily recognize the incision intended line in the subject.

[0117] (Modified example of the first period, the second period, and the cycle T)

[0118] The structure in which the lengths of the first period in which the normal light is irradiated and the second period in which the special light is irradiated are constant in each repetition of the cycle T has been described, but the lengths of the first period in which the normal light is irradiated and the second period in which the special light is irradiated can also not be constant (can also be variable) in each repetition of the cycle T. For example, the ratio of the lengths of the first period and the second period in one cycle T is 3:1, and the ratio of the lengths of the first period and the second period in another cycle T can be 3:2.

[0119] Also, the case in which the repetition cycle of the actions of irradiating the normal light and the special light, that is, the cycle T is constant has been described, but the cycle T can also be variable. Also, the structure in which, in the cycle T, the normal light is first irradiated and then the special light is irradiated has been described, but the structure in which, in the cycle T, the special light is first irradiated and then the normal light is irradiated can also be provided.

[0120] Also, the spectrum of the general light can be constant in each repetition of the period T, or can be non-constant in each repetition of the period T. Likewise, the spectrum of the special light can be constant in each repetition of the period T, or can be non-constant in each repetition of the period T.

[0121] Also, the structure in which the first period in which the general light is irradiated is followed by a second period in which the special light is irradiated is described, but there can be a non-irradiation period in which the light source device 5 does not irradiate the illumination light between the first period and the second period.

[0122] Also, a structure in which narrow-band short-wave dimming and white light are simultaneously irradiated as the general light or the special light described above can be provided. Thereby, a fine difference in color is color emphasized and displayed, and thus observation of inflammation observation or pick-up observation, or the like is easily performed.

[0123] (Another mode of the endoscope system)

[0124] An endoscope device 100 is described as an example of the endoscope system of the present application, but the endoscope system of the present application can be realized by a plurality of devices connected to each other via a network. For example, a structure in which at least a part of the processing based on the control device 4 described above is performed by another device connected to the endoscope device 100 via a network can be provided.

[0125] (Another mode of the display section)

[0126] A display device 7 is described as an example of the display section of the present application, but the display section of the present application can be realized by a plurality of display devices. At this time, the main region described above can be constituted by one of the plurality of display devices, and the sub region described above can be constituted by the remaining display devices among the plurality of display devices.

[0127] (Control program)

[0128] The control program stored in the ROM of the control device 4 is stored in a non-transitory storage medium in which a computer can read a program. Such a "storage medium readable by a computer" includes, for example, an optical medium such as a CD-ROM (Compact Disc-ROM), or a magnetic storage medium such as a USB (Universal Serial Bus) memory or a memory card. Also, such a program can be provided by download via a network.

[0129] As described above, the following matters are disclosed in the present specification. (1)

[0131] An endoscope system including:

[0132] An endoscope includes an imaging unit that images an object to be imaged,

[0133] a light source unit that irradiates the object to be imaged with illumination light,

[0134] an imaging control unit that generates imaging image information based on an imaging signal obtained from the imaging unit, and

[0135] a display unit that displays an imaging image based on the imaging image information,

[0136] the imaging unit images the object to be imaged at a higher frame rate than a display frame rate of the imaging image displayed by the display unit,

[0137] the light source unit repeatedly performs the following actions: continuously irradiates the object to be imaged with illumination light during a first period that spans a plurality of frames based on imaging by the imaging unit, and irradiates the object to be imaged with illumination light having a different spectrum from the illumination light irradiated during the first period during a second period that spans at least one frame based on imaging by the imaging unit. (2)

[0139] The endoscope system according to (1), wherein

[0140] each of the first period and the second period is constant or indefinite when the actions are repeatedly performed. (3)

[0142] The endoscope system according to (1) or (2), wherein

[0143] each of the spectra of the illumination light irradiated by the light source unit during the first period and the second period is constant or indefinite when the actions are repeatedly performed. (4)

[0145] The endoscope system according to any one of (1) to (3), wherein

[0146] there is a non-irradiation period of the light source unit between the first period and the second period. (5)

[0148] The endoscope system according to any one of (1) to (4), wherein

[0149] the imaging unit performs an imaging action in a rolling shutter method,

[0150] the second period is a period that spans a plurality of frames based on imaging by the imaging unit,

[0151] The imaging control section acquires, as the imaging image information for the second period, information other than the imaging image information of one frame based on the imaging by the imaging section. (6)

[0153] The endoscope system according to any one of (1) to (4), wherein

[0154] The imaging section performs an imaging operation of a rolling shutter method,

[0155] The imaging control section performs a global reset of the imaging section after the first period, and acquires, as the imaging image information for the second period, imaging image information after the global reset. (7)

[0157] The endoscope system according to any one of (1) to (4), wherein

[0158] The imaging section performs an imaging operation of a global shutter method. (8)

[0160] The endoscope system according to any one of (1) to (7), comprising an analysis section that performs analysis based on the imaging image information obtained by the imaging during the second period,

[0161] The display section displays the imaging image based on the imaging image information obtained by the imaging during the first period. (9)

[0163] The endoscope system according to (8), wherein

[0164] The display section displays a screen including the imaging image and the analysis result. (10)

[0166] The endoscope system according to (8) or (9), wherein

[0167] The analysis includes analysis of an insertion shape of the endoscope. (11)

[0169] The endoscope system according to any one of (8) to (10), wherein

[0170] The analysis includes extraction of a contour of an imaging image based on the imaging image information. (12)

[0172] The endoscope system according to any one of (8) to (11), wherein

[0173] The analysis includes detection of a region of interest in the subject into which the endoscope is inserted. (13)

[0175] The endoscope system according to any one of (8) to (12), wherein

[0176] The analysis includes selection of similar case images. (14)

[0178] The endoscope system according to any one of (8) to (13), wherein

[0179] The analysis includes discrimination of a tumor and a non-tumor. (15)

[0181] The endoscope system according to any one of (8) to (14), wherein

[0182] The analysis includes determination of a state of an organ. (16)

[0184] The endoscope system according to any one of (8) to (15), wherein

[0185] The analysis includes generation of a cutaway predetermined line. (17)

[0187] The endoscope system according to any one of (1) to (16), wherein

[0188] The first period is longer than the second period. (18)

[0190] The endoscope system according to any one of (1) to (17), wherein

[0191] The light source portion irradiates each illumination light that is white light or light for image-enhanced observation during the first period and the second period. (19)

[0193] A control method of an endoscope system that includes an endoscope including an imaging portion, a light source portion that irradiates an illumination light to an imaging target imaged by the imaging portion, an imaging control portion that generates imaging image information from an imaging signal obtained from the imaging portion, and a display portion that displays an imaging image based on the imaging image information, in the control method of the endoscope system,

[0194] The imaging of the imaging target is performed by the imaging portion at a higher frame rate than the display of the imaging image displayed by the display portion.

[0195] The light source section repeatedly performs the following actions: after continuously irradiating illumination light during a first period spanning a plurality of frames of continuous imaging by the imaging section, irradiating illumination light having a different spectrum from the illumination light irradiated during the first period during a second period spanning at least one frame of imaging by the imaging section. (20)

[0197] A recording medium stores a control program that controls an endoscope system that includes an endoscope including an imaging section, a light source section that irradiates illumination light to an imaging target imaged by the imaging section, an imaging control section that generates imaging image information from an imaging signal obtained from the imaging section, and a display section that displays an imaging image based on the imaging image information, the control program causing a computer to execute processes of,

[0198] causing the imaging section to image the imaging target at a higher frame rate than a display frame rate of the imaging image displayed by the display section,

[0199] causing the light source section to repeatedly perform the following actions: after continuously irradiating illumination light during a first period spanning a plurality of frames of continuous imaging by the imaging section, irradiating illumination light having a different spectrum from the illumination light irradiated during the first period during a second period spanning at least one frame of imaging by the imaging section.

[0200] According to the above description, the imaging device described in the following supplementary item 1 can be grasped.

[0201] [Supplementary item 1]

[0202] An endoscope system includes:

[0203] an endoscope including an imaging sensor;

[0204] a light source device that irradiates illumination light to an imaging target imaged by the imaging sensor;

[0205] an imaging control processor that generates imaging image information from an imaging signal obtained from the imaging sensor; and

[0206] a display device that displays an imaging image based on the imaging image information,

[0207] the imaging sensor images the imaging target at a higher frame rate than a display frame rate of the imaging image displayed by the display device,

[0208] The light source device repeatedly performs the following actions: after continuously irradiating illumination light during a first period spanning a plurality of frames in succession based on imaging by the imaging sensor, irradiating illumination light having a spectrum different from that of the illumination light irradiated during the first period during a second period spanning at least one frame based on imaging by the imaging sensor.

[0209] Industrial applicability

[0210] According to the present application, it is possible to provide an endoscope system, a control method, and a control program that enable display of a high-quality real-time image based on imaging by normal light while also enabling imaging based on special light.

[0211] Symbol explanation

[0212] 1 - endoscope, 4 - control device, 5 - light source device, 6 - input section, 7 - display device, 10 - insertion section, 10A - flexible section, 10B - bending section, 10C - distal end section, 11 - operation section, 12 - bend knob, 13 - universal cord, 13A, 13B - connector sections, 21 - objective lens, 22 - lens group, 23 - imaging element, 25 - memory, 26, 41 - communication I / F, 27 - imaging drive section, 42 - signal processing section, 42a - imaging image information generation section, 42b - real-time image generation section, 42c - analysis section, 42d - analysis image generation section, 43 - display controller, 44 - system control section, 45 - recording medium, 50 - illumination lens, 51 - light source processor, 52 - light source section, 52a - V-LED, 52b - B-LED, 52c - G-LED, 52d - R-LED, 53 - light guide, 54 - optical path coupling section, 60 - imaging surface, 61 - pixel, 62 - pixel row, 63 - drive circuit, 64 - signal processing circuit, 70 - screen, 71 - main screen, 72 - sub screen, 81 - illumination light timing, 82 - imaging timing, 82a, 82b, 82c, 82d, 82e - imaging, 83 - main screen display timing, 83a - main screen display, 84 - sub screen display timing, 84b, 84c - sub screen display, 91 - global reset, 100 - endoscope device.

Claims

1. An endoscope system comprising: an endoscope including an imaging unit; a light source unit that irradiates a white light and a special light having a spectrum different from that of the white light to an imaging target imaged by the imaging unit; an imaging control unit that generates imaging image information from an imaging signal obtained from the imaging unit; and a display unit that displays an imaging image based on the imaging image information, including a main screen and a sub screen, the light source unit repeatedly performing the following actions: continuously irradiating the white light during a first period spanning a plurality of frames based on imaging by the imaging unit, and then irradiating the special light during a second period spanning at least one frame based on imaging by the imaging unit, acquiring a plurality of white light images imaged during the first period at a first imaging frame rate, acquiring a plurality of special light images imaged during the second period at a second imaging frame rate, displaying the plurality of white light images on the main screen, displaying the plurality of special light images on the sub screen, and the first imaging frame rate being higher than a frame rate of display of the plurality of white light images.

2. The endoscope system according to claim 1, wherein each of the first period and the second period is constant when the actions are repeatedly performed, or is indefinite when the actions are repeatedly performed.

3. The endoscope system according to claim 1 or 2, wherein the spectrum of the white light irradiated during the first period and the spectrum of the special light irradiated during the second period are constant when the actions are repeatedly performed, or are indefinite when the actions are repeatedly performed.

4. The endoscope system according to claim 1 or 2, wherein there is an irradiation-free period of the light source unit between the first period and the second period.

5. The endoscope system according to claim 1 or 2, wherein the imaging unit performs an imaging action of a rolling shutter type, the second period is a period spanning a plurality of frames based on imaging by the imaging unit, and the imaging control unit acquires, as imaging image information of the second period, information other than imaging image information based on at least one frame amount of imaging by the imaging unit with respect to the imaging image information immediately after the start of the second period.

6. The endoscope system according to claim 1 or 2, wherein the imaging unit performs an imaging action of a rolling shutter type, and the imaging control unit performs a global reset of the imaging unit after the first period, and acquires imaging image information after the global reset as imaging image information of the second period.

7. The endoscope system according to claim 1 or 2, wherein the imaging unit performs an imaging action of a global shutter type.

8. The endoscope system according to claim 1 or 2, comprising an analysis unit that performs analysis based on imaging image information obtained through imaging during the second period among the imaging image information, and the display unit displays the imaging image based on imaging image information obtained through imaging during the first period among the imaging image information.

9. The endoscope system according to claim 8, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The display section displays a screen including the captured image and the analysis result.

10. The endoscope system according to claim 8, wherein The analysis includes analysis of an insertion shape of the endoscope.

11. The endoscope system according to claim 8, wherein The analysis includes extraction of a contour of a captured image based on the captured image information.

12. The endoscope system according to claim 8, wherein The analysis includes detection of a region of interest in a subject into which the endoscope is inserted.

13. The endoscope system according to claim 8, wherein The analysis includes selection of a similar case image.

14. The endoscope system according to claim 8, wherein The analysis includes discrimination of a tumor and a non-tumor.

15. The endoscope system according to claim 8, wherein The analysis includes determination of a state of an organ.

16. The endoscope system according to claim 8, wherein The analysis includes generation of a cut-off predetermined line.

17. The endoscope system according to claim 1 or 2, wherein The first period is a period longer than the second period.

18. A control method of an endoscope system in which The endoscope system includes an endoscope including an imaging section, a light source section that irradiates a white light and a special light having a spectrum different from that of the white light to an imaging object imaged by the imaging section, an imaging control section that generates captured image information from an imaging signal obtained from the imaging section, and a display section that displays a captured image based on the captured image information, including a main screen and a sub screen, and in a control method of the endoscope system, The light source section repeatedly performs the following actions: after continuously irradiating the white light for a first period that spans a plurality of frames continuously based on imaging by the imaging section, the special light is irradiated for a second period that spans at least one frame based on imaging by the imaging section, a plurality of white light images imaged at the first period at a first imaging frame rate are acquired, a plurality of special light images imaged at the second period at a second imaging frame rate are acquired, the plurality of white light images are displayed on the main screen, the plurality of special light images are displayed on the sub screen, the first imaging frame rate is higher than a frame rate of display of the plurality of white light images.

19. A recording medium storing a control program that controls an endoscope system including an endoscope including an imaging section, a light source section that irradiates a white light and a special light having a spectrum different from that of the white light to an imaging object imaged by the imaging section, an imaging control section that generates captured image information from an imaging signal obtained from the imaging section, and a display section that displays a captured image based on the captured image information, including a main screen and a sub screen, the control program being for causing a computer to perform processing of causing the light source section to repeatedly perform the following actions: after continuously irradiating the white light for a first period that spans a plurality of frames continuously based on imaging by the imaging section, the special light is irradiated for a second period that spans at least one frame based on imaging by the imaging section, acquiring a plurality of white light images imaged during the first period at a first imaging frame rate, acquiring a plurality of special light images imaged during the second period at a second imaging frame rate, displaying the plurality of white light images on the main screen, displaying the plurality of special light images on the sub screen, the first imaging frame rate is higher than a frame rate of display of the plurality of white light images.

Images